The present invention relates to a method of producing metal composite materials such as cemented carbide.
U.S. Pat. No. 5,505,902 discloses a method in which one or more metal salts of at least one iron group metal containing organic groups are dissolved in at least one polar solvent such as ethanol, methanol and water, and complex bound with at least one complex former comprising functional groups in the form of OH or NR.sub.3 (R=H or alkyl). Hard constituent powder and, optionally, a soluble carbon source are added to the solution. The solvent is evaporated and the remaining powder is heat treated in inert and/or reducing atmosphere. As a result, a hard constituent powder coated with at least one iron group metal is obtained, which after the addition of a pressing agent, can be compacted and sintered according to standard practice to form a body containing hard constituents in a binder phase.
When making submicron cemented carbide, i.e., with a WC grain size of &lt;1 .mu.m, grain growth inhibitors have to be added in order to avoid WC grain growth during sintering. Examples of such grain growth inhibitors are VC, Cr.sub.3 C.sub.2. The above mentioned patent discloses a method of depositing a layer of binder metal onto the surfaces of the hard constituent grains. It is, however, desirable to also be able to precipitate at the same time, the elements inhibiting grain growth.